Mask-to-mask resuscitation systems



June 27, 1967 G. BARTLETT, JR

MASK-TO-MASK RESUSCITATION SYSTEMS 2 Sheets-Sheet Filed Aug. 12, IP64 INVENTOR.

Roscoe G. rflefl ,Jr.

Attorney June 27, 1967 a. e. BARTLETT, JR

MASKTO'MASK RESUSCITATION SYSTEMS 2 Sheets-Sheet 2 Filed Aug. 12, 1964 mmwmwowmi u @N m n vh m a y Q mkohdimmo I NVEN TOR. Roscoe G. Bort|ett,Jr.

Aftor ey United States Patent Office 3,3217% Patented June 27, 1967 5,327,704 MASK-TO-MASK RESUSCETATION SYSTEMS Roscoe G. Bartlett, .Ir., Lime Kiln, Md. 21763 Filed Aug. 12, 1964, Ser. No. 389,039 13 Claims. (Cl. 128-1455) ABSTRACT OF THE DISCLOSURE The present invention is directed to a resuscitation system of the type wherein the rescuer and victim are equipped with facemasks. More particularly, these masks are interconnected in a closed loop such that the rescuers expirations pass into the Victims lungs and the rescuer rebreathes the victims discharge after it has been treated for carbon dioxide removal. The rescuer may be supplied with oxygen on a demand basis and may use a rebreather to further reduce the oxygen expenditure.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalities thereon or therefor.

The present invention relates generally to apparatus for assisting individuals whose respiratory requirements cannot be satisfied either because of an insufficiency of oxygen in the envronment or because of a temporary interruption of their breathing mechanism as a result of, for example, a paralytic or gas attack and, more particularly, to respiratory apparatus which can be quickly and simply switched between a multiplicity of different ventilating and operational modes.

In the so-called mouth-to-mouth resuscitation method, the rescuers expired breath in forced directly into the victims lungs in an effort to restore these organs to their normal operation. Where the emergency occurs in an aircraft or a space vehicle, the oxygen masks, if fitted with pressure-compensated exhalation valves, can be utilized in a variation of this mouth-to-mouth method. More particularly, one mask can be fitted over the victims face and the rescuer, either utilizing the remote and disconnected end of the oxygen supply line of this mask as a mouthpiece or coupling this line to the exhaust line of his own mask, can discharge his exhalations into the victims system. This procedure may be considered as maskto-mask resuscitation arrangement.

In ordinary breathing activity, only a very small portion, less than 2% of the metabolic rate, is concerned with the maintenance of the breathing movements. And even when the metabolic cost of breathing is increased by the individual breathing both for himself and a paralyzed patient, the total energy spent still represents only a very small portion of the cost of the total metabolic activity. It is thus theoretically possible for one person to supply the breathing power for two individuals for a relatively long period of time. In actual practice, mouth-to-mouth resuscitation has been continued by one operator over a period of several hours without severe fatigue. With the invention hereinafter to be described, much less fatigue accompanies the operation since the operator need not repeatedly remove his mouth from the air passageway leading to the victim between breaths.

When the rescuer is coupled to an oxygen supply system, it has been found that a victim ventilated with his expirations receives a mixture which contains approximately 96% oxygen and 4% carbon dioxide, a composition which approaches the ideal combination of gases for resuscitation under many emergency situations.

In the system of the present invention, the victim can be supplied with such a mixture. Also, a closed loop can be effected in the circuit which permits the oxygen in the victims expirations to be reclaimed for further use by the rescuer. In an alternative mode, the invention can be used in a mask-to-mask resuscitation system without oxygen, that is, with the rescuer breathing air from the local environment. Moreover, by removing the victims mask from the circuit, the system can be transformed into a rebreather escape device with oxygen which can be operated in an open circuit or in a closed circuit mode. Each and any of the above ventilating and operational modes may be readily selected by the rescuer, and the necessary connection can be simply and quickly made with a minimum of inconvenience.

In an alternative embodiment of the present invention, the system is provided with a maual bellows which assists the operators exhalations when compliance of the victims chest must be increased because of, for example, nerve gas poisoning.

It is accordingly a primary object of the present invention to provide a versatile system for emergency pulmonary resuscitation wherein the rescuer and the victim can be ventilated with either oxygen or air in a mask-tomask rescue method.

Another object of the present invention is to provide an oxygen breathing system wherein the victim can be ventilated by the expirations of the rescuer who can elect at his option to breathe oxygen or air in an open or closed system.

Another object of the present invention is to provide a respiratory system wherein rescuer and victim are intercoupled in a facemask-to-facemask circuit with either an oxygen or air input which can be either in an open or closed circuit.

A yet still further object of the present invention is to provide a versatile arrangement of interconnected facemasks, oxygen supply, carbon dioxide absorber and rebreathing bellows which can be utilized in a variety of different breathing and ventilating modes.

A yet still further object of the present invention is to provide a facemask-to-facemask resuscitation system having a rebreathing provision for minimizing the oxygen requirements of the system.

A yet still further object of the present invention is to provide an emergency resuscitation system utilizing a pair of facemasks which can be quickly transformed into a closed rebreathing circuit for one of the parties involved in the operation.

Another object of the present invention is to provide an emergency resuscitation system wherein the victim may be ventilated by the operators exhalations assisted by manual means which delivers oxygen to the victim under pressure and alternatively assists his passive exhalation.

Briefly and in somewhat general terms, the above objects of invention are realized in one preferred embodiment of the invention by providing the rescuer or operator with a facemask equipped with check valves which allow either air or oxygen to flow into his facemask area and his discharge to pass out therefrom and by providing the victim with a similar facemask but one designed for pressure breathing. In this latter type of mask, it will be appreciated, the discharge valve is pressure-compensated so as to open only in response to the wearers exhalations. This type of mask is necessary for the victim in order to prevent air or oxygen forced into his facemask area by the rescuers exhalations from passing directly out therefrom and, in effect, shunting his respiratory system.

The input or inhalation line of the rescuers facemask is coupled via a quick disconnector, demand valve and a pressure reducer to an oxygen supply. When this disconnect is broken, the rescuer breathes air from the surrounding environment. At all other times, he breathes pure oxygen from the supply on a demand basis. The input passageway of the rescuers mask is also connected to a rebreather bellows while the output or exhalation passageway is coupled by means of a suitable interconnecting line to the input or inhalation passageway of the victims mask. And lastly, the output or exhalation passageway of the victims mask is Connected to one side of a carbon dioxide absorber, the other side of which is coupled to the rebreathing bellows. Each of the connectors used to intercouple the above components in the manner described above is of a quick disconnect type, and this feature permits the system to be arranged in a variety of configurations corresponding to diflierent operational and breathing modes.

In an alternative embodiment of the present invention, the rescuer and the victim are interconnected in a maskto-mask open or closed loop system with an oxygen supply and carbon dioxide absorber included therein. However, the rebreathing bellows is replaced by a manually operated bellows. This bellows provides efiicient ventilation for an apneic victim and also creates a negative pressure in the system which aids the pressure exhalation of the victim.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invent-ion when considered in conjunction with the accompanying drawings wherein:

FIG. 1 schematically illustrates one modification of the present invention; and

FIG. 2 illustrates an alternative embodiment of the present invention having a manual assist for reviving certain types of gas victims.

Referring now to FIG. 1 which schematically illustrates the various components interconnected in a mask-tomask resuscitation mode with an oxygen closed circuit loop, it will be seen that the apparatus includes a first facernask 1, the so-called rescuers mask, provided with a flexible inlet line 2 and a flexible exhaust line 3 which both lead into and communicate with the facemask area. Positioned within inlet line 2 is a conventional, normally closed check valve 5 which is arranged to open when the pressure level within the facemask area is less than that within the lower portion of this line. Positioned likewise within exhaust line 3 is a normally closed check valve 4 which is arranged to open only when the pressure level within the facemask area is greater than that within the lower portion of this line. Valves 4 and 5, it will be appreciated, operate in a sequential manner during the inspirational and expirational portions of the rescuers breathing cycle to allow him to breathe oxygen or air and discharge his expirations from the facemask area.

Valve 4 normally vents the individuals exhalations into the atmosphere but, in the present system, as will be seen hereinafter, these exhalations are used to revive the victim.

Inlet line 2, in this modification, has a flexible branch line 6 coupled to a sidewall portion thereof and, coupled to the open end of this branch line by means of a quick disconnector 8 is an oxygen supply line 9 which includes a combined demand valve and pressure reducer 10 and terminates in an oxygen supply 11 having oxygen under pressure stored therein.

Inlet line 2 is also coupled at its lower terminal portion 12 to a flexible line 13 via a quick disconnector 7. Line 13 leads to a flexible rebreathing bellows 14 and has a branch'line 15 coupled to a side portion thereof which terminate at one side of a carbon dioxide absorber 17, the other side of which is connected to a flexible air passageway 19 and by a quick disconnector 2d to exhaust line 21 of the victims facemask 22. The last link in the circuit is an air passageway or conduit 23 which is connected to the exhaust line 3 of the rescuers facemask 1 and the input line 26 of the victims facemask 22 by quick disconnectors 24 and 25 fastened thereto.

As-briefly mentioned hereinbefore, the victims facemask 22 contains an exhalation valve of the pressurecompensated type. Thus, this mask has a check valve 28 in its input line 26 and a pressure-compensated check valve 29 in its exhaust line 21. To show the nature of the latter valve, the circuit includes a small pressure balancing passageway 27 intercoupling the input line 26 and the output line 21 below the valve locations. This line, during the rescuers exhalations, applies .a counterbalancing pressure to the lower side of valve 29, thus maintaining this valve closed when the pressure in the victims facemask area builds up during the air transfer process. Without this feature, the rescuers expirations might pass directly through valve 28 and out valve 29 without entering the victims respiratory system. Valve 29, consequently, can only be opened by the victims passive exhalations. It will thus be seen that valves 28 and 29 operate sequentially during mutually exclusive periods corresponding respectively to the rescuers expirational eifort and the victims expirational effort.

When the system is interconnected in the manner shown, the rescuers breathing requirements are satisfied first with the gas mixture available within rebreathing bellows 14- and then with oxygen from storage container 11. It would be pointed out that rebreathing accumulator 14 can take the form of either a simple, thin-walled, polyethylene bag or a pleated, accordion-type rubber bellow-s. The latter design has several advantages. First of all, the volume displacement of the device when in use can be reduced by constructing the bellows so that it normally operates from a collapsed rather than a full position. Also, the use of rubber in the construction of this reservoir results in a more durable device.

As the rescuer commences to breathe, his inspirational efiorts or one prolonged deep effort will open valve 5 and couple input line 2 to rebreathing bellows 14. If this bellows is not in a collapsed position, the rescuers breathing demands at first will be satisfied from the air mixture stored therein. However, after this mixture is expended, his further breathing will create a negative pressure in lines 2, 13 and 6, and pressure reducer-demand valve 10 will open to couple the oxygen supply to the facemask. Thereafter, oxygen, at a reduced pressure and in an amount determined by the rescuers respiratory demands, will flow intermittently from oxygen storage device 11 via pressure reducer and demand valve 10 into the facemask area, and the individuals expirations will pass out via exhaust valve 4 into line 23.

The pressure reducer is included in the oxygen supply line to permit a demand valve of a nominal pressure design to be utilized therein. The operation of a conventional demand valve in an oxygenating system of the type so far described is .well known and, since this valve performs in its usual manner, its precise structure and coaction with the other elements of the system will not be described in detail.

In the exhalation portion of the rescuers breathing cycle, his discharge passes through exhaust valve 4 into line 3 and thence through line 23, into the input line 26 of the victims facemask 22. Each exhalation opens valve 28 and passes into the victims respiratory system. A relatively small amount of this discharge is diverted by line 27 against the lower portion of pressure compensated valve 29, thus establishing equal pressures on opposite sides of this valve and maintaining it closed during the air transfer rescue process. Because of the close fit of the victims facemask, there is substantially no leakage and all of the rescuers discharge ventilates the victim. The elastic recoil of the victims chest and lungs brings about his expiration, and this expiration, which takes place during the rescuers inspiration, opens valve 29 and passes via line 19 into the carbon dioxide absorber 17 from whence it flows with the carbon dioxide removed into line 15, line 13 and rebreather 14.

From a study of the above circuit, it will be seen that the system includes a closed circulating loop whereby oxygen periodically introduced on demand into this system from storage element 11, after use first by the rescuer and then by the victim, passes into a rebreathing storage bellows from which it can be subsequently reused by the rescuer in accordance with his breathing needs. The presence of the rebreathing bellows in the rescuers portion of the system minimizes the amount of oxygen required from the oxygen supply, thus extending the lifetime of this supply by approximately twelve-fold and raising the overall efiiciency of the system.

The above apparatus can be transformed into an open circuit resuscitator with oxygen by merely breaking the connection at point B and the self-sealing connection at D, thereby removing the carbon dioxide absorber and the rebreathing bellows from the circuit. With these last two components no longer present, the rescuer is still supplied with fresh oxygen from storage source 11 on demand, but the victims discharge, instead of being reclaimed, is vented directly into the environment.

In a third mode, the oxygen supply and its affiliated pressure reducer and demand valve can be removed from the system by breaking the connection at point C and, with connection B still broken and D self-sealed, the system becomes a mask-to-mask resuscitator Without oxygen. In this configuration, the rescuer inhales air from the surrounding environment through the open end of section 6, and the victims exhalations again pass out of the system into the surrounding atmosphere.

With the victims facemask 22 removed from the circuit and line 23 eliminated and line 19 inserted into the exhaust line 3 of the rescuers facemask and connections C and D re-established, the apparatus becomes a rebreather escape device with oxygen. In this mode, the individual wearing facemask 1 discharges his expirations directly into the carbon dioxide absorber 17, from whence they pass with the carbon dioxide removed therefrom into lines 13 and then into rebreathing bellows 14. Mask 1 thus has a closed loop in its discharge circuit which permits the wearer to rebreathe his discharge after treatment in the carbon dioxide absorber, thus cutting down the oxygen consumption from supply source 11. When the apparatus is used in the above configuration, it may be preferable to use a thin wall, rubber bellows as rebreather 14, for with such a construction a subsequent expiration after a deep inspiration would simply fill this bellows to its capacity and then blow it up like a balloon. This would accommodate the larger expirations with only a noticeable increase in pressure at the end of expiration. Such an increase in pressure would warn the deep breather of potential hyperventilation if he were to continue his deep breathing.

Lastly, with the victims mask, the carbon dioxide absorber 17 and the rebreathing bellows detached, the device becomes an open circuit escape device wherein the indi viduals breathing demands are satisfied with pure oxygen from storage supply 11, and his discharge vented into the surrounding atmosphere. In this configuration, line 12 would be closed as described above to isolate the input line 2 from the atmosphere.

FIG, 2 illustrates an alternative embodiment of the present invention which includes a manually operated bellows as a replacement for the rebreather of FIG. 1 for increasing the effectiveness of the resuscitation attempt with certain gas victims. This arrangement provides a manual assist for the rescuer or operators exhalations when compliance of the victims chest must be increased as a result of, for example, nerve gas poisoning. Here, as in FIG. 1, an oxygen supply source 49, in combination with a pressure reducer 41 and a conventional demand valve 42, provide the rescuer with ox gen on a demand basis. The operator again wears a facemask 43 having check valves 44 and 45 in its air passageways which operate sequentially during the inhalation and exhalation portions of his breathing cycle to control the flow of oxygen or an air-oxygen mixture into his facemask area and the passage of his exhalations out therefrom. The victim or patient is likewise fitted with a facemask 46 of the type more fully described in connection with the system of FIG. 1.

Coupled to the oxygen supply line 47 in this system is a branch line 48 which leads into and communicates with the interior of a manually operated bellows 49. This bellows, which can be of conventional design, has a check valve 50 mounted in a side wall portion thereof which can, at the option of the operator, be rendered ineffective by, for example, being locked or covered by a suitable closure cap 51. When this valve is unlocked or uncovered, bellows 49 operates in its usual fashion, drawing in either air from the surrounding atmosphere or oxygen from supply source 40 during the expansion and discharging air or oxygen from its nozzle during its contraction. Coupled to branch line 48 is a flexible line 51, and the open end of this line is connected by means of quick disconnector 52 to the inlet line 53 of the operators facemask. Discharge line 54 of this facemask is connected by quick disconnector 56 to line 55, which, in turn, is coupled by disconnector 57 to the inlet line of the patients mask, the discharge line 58 of which is connected by means of line 59, having a carbon dioxide absorber 60 incorporated therein, back to the oxygen supply line 47. A quick disconnector 61 of the self-sealing type is also included in line 59 in the link between the carbon dioxide absorber and branch line 48. All lines to the facemasks, it should be appreciated, are equipped with quick disconnectors.

When the apparatus is interconnected in the manner above described, the system, it will be appreciated, con tains a closed rebreathing loop which, as in the case of FIG. 1, permits all of the victims discharge, except for the absorbed carbon dioxide, to be used before fresh oxygen is withdrawn from supply source 40. Line 59, it would be mention, is also provided with a manual valve 62 which in one position vents this line to the atmosphere.

The system of FIG. 2 can be arranged to perform as a manual resuscitator with an oxygen closed circuit loop by disconnecting the operators facemask 43 with its lines 5.? and 54 and mating the male and female portions of disconnectors 52 and 56, thereby joining lines 51 and 55 and providing continuity for the air flow from bellows 49 to the patients mask. With the operators facemask removed and valves 50 and 62 closed, oxygen is drawn from supply source 40 into the interior of bellows 49 when this unit is expanded since demand valve 42 sensing the negative pressure in lines 47 and 48 brought about by this expansion opens to permit this flow. This oxygen 49 is discharged during the contraction of this unit and forced through lines 51 and 55 into the facemask area of mask 46 and into the victims respiratory system. As an optional element, a check valve may be included in line 4b to prevent any of this discharge from being diverted and dissipated in lines 47 and 59 and the apparatus connected thereto. Because bellows 49 imparts a high velocity to the oxygen flow and delivers this oxygen to the victim under pressure, this particular operational mode provides effective ventilation for an apneic or nonbrearthing victim. The victims discharge, as in the system of FIG. 1, passes out line 58 into line 59, through the carbon dioxide absorber 60, line 48 and into bellows 49 when this unit is next expanded. Consequently, all of this discharge, except the absorbed carbon dioxide, contributes to the breathing mixture sent to the patient for his next inhalation effort. It should be appreciated that the expansion of bellows 49 creates a negative pressure in the system which also assists the passive exhalation of the victim.

To transform the above system into a manual resuscitator with oxygen and an open circuit configuration, it is only necessary to shift valve 62 manually to an open condition, all other connections being left the same as in the above mode. When this change is made, the victims exhalations are not recirculated but are vented by valve 59 into the surrounding atmosphere. The same results can be accomplished by removing line 59 with the carbon dioxide absorber included therein and line 58 from the system, self-sealing disconnector 61 closing at this time to seal the otherwise open end of stub line 63.

When valve 62 is a component of this system, the .ap-. paratus can be switched back and forth from an open circuit to a closed circuit system in order, for example, to flush the victims lungs, for purging inert gases, such as those inhaled at high altitudes or contaminants, such as carbon monoxide.

The self-sealing disconnectors utilized at location D in FIG. 1 and location F in FIG. 2 can take many forms. For example, these connectors may merely consist of .a terminating check valve member spring biased normally to a closed position and adapted to be displaced to and held in an open position when the mating male portion is inserted therein. Various other devices, of course, can be used to accomplish this simple function.

It will be appreciated that any conventional quick-acting type of disconnector can be used in the present invention. For example, a simple, friction-type male and female fitting can be used at each site. Also, these fittings can be of the bayonet type or the type that lock in place when one of the elements is pushed in, then rotated with respect to the other. Since these fittings merely have to establish a continuity of air flow in the system, they can, as mentioned hereinbefore, be constructed from a wide variety of designs and, consequently, no detailed description of these elements is deemed necessary for an understanding and appreciation of the invent-ion above described.

As mentioned hereinbefore, valve 62 is included in the victims exhaust line to vent his discharge into the atmosphere. This valve can be arranged to rotate to a position where it not only vents line 59 but also closes it further on downstream to prevent the victims discharge from needlessly passing through the carbon dioxide absorber and into the rest of the system.

In the arrangement of FIG. 2 heretofore described, bellows 4-9 can be coupled either to supply line 53 of fac mask 43 or to line 55 coupled to the supply line of the patients facemask 48, depending upon the particular mode of ventilation selected. Instead of this alternative ar-rangement, line 51 can be modified so as to terminate in not one but two quick disconnectors, and line 55 similarly modified. The second connectors of these two lines can be interconnected in the manner shown by the dotted portion of FIG. 2 to make the system somewhat more versatile.

For illustrative purposes in the arrangements of FIG. 1 and 2, each of the facemasks was shown as having a separate inlet and outlet passageway communicating with the facemask area. However, it should be appreciated that each mask may be of the type having a single passageway leading into this area that subdivides at an exterior point to form separate branches. In this case, of course, the check valves would be disposed in each of these branches to perform their assigned functions. Also, it would be appreciated that the individual components of the systems of FIGS. 1 and 2 can be mask-mounted or otherwise relocated to consolidate the apparatus and facilitate its operation.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. In a resuscitation system of the type in which the rescuers respiratory discharge is utilized to ventilate the Victim, the combination of a first facemask for use by said rescuer,

. said facernask being provided with an open-ended supply line and an open-ended discharge line;

means connected to said supply line for supplying fresh oxygen on a demand basis to said rescuer;

a second facemask for use by said victim,

said second facemask having an open-ended supply line and an open-ended discharge line,

said second facemask being designed for pressure breathing whereby said discharge line is open only during the exhalation portion of the victims breathing cycle;

means interconnecting the discharge line of said first facemask and the supply line of said second facemask and the discharge line of said second mask and the supply line of said first mask in a closed loop whereby the rescuers discharge ventilates the victim and the victims discharge is available for rebreathing by the rescuer;

and means for lowering the carbon dioxide content of the victims discharge prior to the rescuers rebreathing thereof.

2. In an arrangement as defined in claim 1,

a rebreathing bellows coupled to the supply line of said first facemask for minimizing the amount of fresh oxygen needed to satisfy the breathing requirements of the rescuer.

3. In an arrangement as defined in claim 1 wherein said means connected to said supply line for supplying fresh oxygen on a demand basis to said rescuer can be detached from said supply line and said rescuer breathe air from the surrounding environment instead of oxygen.

4. In an arrangement as defined in claim 1 wherein the means interconnecting the discharge line of said second facemask and the supply line of said first facemask can be detached from the system and the victims discharge expelled into the local environment.

5. In a resuscitation system of the type in which the rescuers respiratory discharge is employed to ventilate the victim, the combination of a first faceniask adapted to be worn by said rescuer,

said first facemask having a supply and discharge line leading into said facemask area;

means coupled to said supply line for supplying said rescuer with oxygen on a demand basis;

a second facemask adapted to be worn by said victim,

said second facemask having a supply and discharge line leading into said facemask area,

said second facemask being designed for pressure breathing whereby said discharge line is opened only during the exhalation portion of the victims breathing cycle;

a detachable first air passageway connecting the discharge line of said first facemask to the supply line of said second facemask;

a detachable second air passageway interconnectig the discharge line of said second facemask to the supply line of said first facemask whereby said first and second facemasks are connected in a closed air recir'cuating loop;

a carbon dioxide absorber associated with said second air passageway for lowering the carbon dioxide content discharged by said victim and subsequently inspired by said rescuer;

and a rebreathing accumulator connected to the supply line of said first facernask for minimizing the amount of fresh oxygen that must be supplied to said rescuer.

6. In an arrangement as defined in claim 5 wherein said means for supplying said rescuer with oxygen on a demand basis includes a supply of compressed oxygen;

a reducing valve coupled to said supply for lowering the pressure of oxygen released therefrom;

and a demand valve, one side of said demand valve being detachably coupled to the supply line of said first facemask, the other side of said demand valve being coupled to the low pressure side of said pressure reducer.

7. In an arrangement as defined in claim means for supplying said victim with oxygen on a demand basis, said last-mentioned means including a supply of compressed oxygen and a combined pressure reducer and demand valve coupled thereto, one side of said combined pressure reducer and demand valve being coupled to said supply and the other side being detachably connected to the supply line of said first facemask.

8. In an arrangement as defined in claim 7 wherein said other side of said comibned pressure reducer and demand valve is detachably connected to the supply line of said first facemask by a quick disconnect which, when broken, allows said rescuer to breathe air from the surrounding environment to satisfy his respiratory requirements.

9. In a resuscitation system of the type in which the rescuers respiratory discharge is utilized to ventilate the victim, the combination of a first facemask,

said facemask being provided with an open-ended supply line and an open-ended discharge line;

a first check valve positioned within said supply line,

said first check valve being normally closed and opening when the pressure within said facemask area is less than the ambient pressure;

a second check valve mounted in said discharge line,

said second check valve being normally closed and opening in response to the exhalation efforts of the individual wearing said facemask;

a second facemask,

said second facemask being provided with an open-ended supply line and an open-ended discharge line;

a third check valve positioned within the supply line of said second facemask,

said third check valve being normally closed and opening only when the pressure Within said facemask area is less than the pressure at the open end of the supply line of said second facemask; a pressure-compensated valve mounted in the discharge line of said second facemask,

said pressure-compensated discharge valve opening only in response to the exhalation efiorts of the individual wearing said facemask; means coupled to the supply line of said first facemask for feeding fresh oxygen into said supply line in accordance with the breathing demands of the individual wearing said facemask; air passageways interconnecting the open end of the discharge line of said first mask to the open end of the supply line of said second facemask and the open end of the discharge line of said second facemask to the open end of the supply line of said first mask;

a rebreathing bellows coupled to the supply line of said first facemask for reducing the amount of fresh oxygen that is required to satisfy the breathing requirements of the individual wearing said first facemask;

and a carbon dioxide absorber positioned within the air passageway interconnecting the opened end of the discharge line of said second facemask to the open end of the supply line of said first facemask for reducing the carbon dioxide content of the air discharged by the individual wearing said second facemask.

19. In a resuscitation system of the type in which the rescuers respiratory discharge is utilized to ventilate the victim, the combination of a first facemask adapted to be. worn by said rescuer,

said first facemask having an open-ended supply line and an open-ended discharge line coupled thereto,

a second facemask adapted to be worn by said victim,

said second facemask having an open-ended supply line and an open-ended discharge line coupled thereto, said second facemask being designed for pressure 5 breathing whereby said discharge line is open only during the exhalation portion of the victims breathing cycle;

means for interconnecting the discharge line of said first mask to the supply line of said second mask and the discharge line of said second mask to the supply line of said first mask in a close-d recirculating loop;

means coupled to said loop for supplying fresh oxygen to the supply line of said first facemask in accordance with the breathing requirements of said rescuer;

a manually operated bellows coupled to said loop;

and a carbon dioxide absorber positioned within said loop for lowering the carbon dioxide content of the air circulating therearound.

11. In a resuscitation system of the type in which the rescuers respiratory discharge is utilized to ventilate the victim, the combination of a first facemask adapted to be worn by said rescuer,

said first facemask having an open-ended supply line and open-ended discharge line coupled thereto;

a second facemask adapted to be worn by said victim,

said second facemask having an open-ended supply line and an open-ended discharge line coupled thereto,

said second facemask being designed for pressure breathing whereby said discharge line is open only during the exhalation portion of the victims breathing cycle;

a first air passageway interconnecting the discharge line of said first mask to the supply line of said second mask;

a second air passageway interconnecting the discharge line of said second facemask and the supply line of said first facemask;

a carbon dioxide absorber positioned in said second air passageway;

a source of compressed oxygen;

a pressure reducer coupled to said source of compressed oxygen;

a demand valve,

one side of said demand valve being coupled to the low pressure side of said pressure reducer and the other side being connected to said second air passageway whereby said rescuer can breathe fresh oxygen on a demand basis;

a manually operated bellows connected to said second passageway;

and means for detaching said first facemask from the system and interconnecting said first and second air passageways whereby said victim can be directly ventilated with the discharge from said bellows.

12. In an arrangement as defined in claim 10 wherein a section of said second air passageway including the carbon dioxide absorber mounted therein may be removed from the closed loop whereby the victims discharge is expelled into the local environment.

13. In a resuscitation system of the type in which the rescuers respiratory discharge is employed to ventilate the victim, the combination of a first facemask adapted to be worn by said rescuer,

said first facemask having a supply and discharge line leading into said facemask area;

means coupled to said supply line for supplying said rescuer with oxygen on a demand basis;

a second facemask adapted to be worn by said victim,

said second facemask having a supply and discharge line leading into said facemask area, said second facemask being designed for pressure breathing whereby said discharge line is opened 1 i only during the exhalation portion of the victims breathing cycle;

a first air passageway connecting the discharge line with said first facernask to the supply line of said second mask;

a second air passageway coupled to the discharge line of said second facernask;

a carbon dioxide absorber positioned within said second air passageway;

a third air passageway connecting said second air pas- 1O sageway to the supply line of said first facemask;

means for coupling fresh oxygen to said third passageway in accordance with the respiratory requirements of the individual Wearing said first facernask;

a manually operated bellows coupled to said third passageway;

and means for disconnecting the supply line and discharge line of said first facemask from said first and third air passageways and for interconnecting said first and third passageways whereby said victim can be ventilated by the discharge from said bellows.

References Cited UNITED STATES PATENTS 374,402 12/1887 Fell 128-29 3,200,816 8/1965 Bartlett 128142 3,208,449 9/1965 Bartlett 128-142 FOREIGN PATENTS 216,459 5/1924 Great Britain.

901,357 7/1962 Great Britain.

934,973 8/1963 Great Britain.

RICHARD A. GAUDET, Primary Examiner.

K. L. HOWELL, Assistant Examiner. 

1. IN A RESUSCITATION SYSTEM OF THE TYPE IN WHICH THE RESCUER''S RESPIRATORY DISCHARGE IS UTILIZED TO VENTILATE THE VICTIM, THE COMBINATION OF A FIRST FACEMASK FOR USE BY SAID RESCUER, SAID FACEMASK BEING PROVIDED WITH AN OPEN-ENDED SUPPLY LINE AND AN OPEN-ENDED DISCHARGE LINE; MEANS CONNECTED TO SAID SUPPLY LINE FOR SUPPLYING FRESH OXYGEN ON A DEMAND BASIS TO SAID RESCUER; A SECOND FACEMASK FOR USE BY SAID VICTIM, SAID SECOND FACEMASK HAVING AN OPEN-ENDED SUPPLY LINE AND AN OPEN-ENDED DISCHARGE LINE, SAID SECOND FACEMASK BEING DESIGNED FOR PRESSURE BREATHING WHEREBY SAID DISCHARGE LINE IS OPEN ONLY DURING THE EXHALATION PORTION OF THE VICTIM''S BREATHING CYCLE; 